by Bob Nightengale, USA TODAY Sports

by Bob Nightengale, USA TODAY Sports

He knows there are people out there convinced he's cheating, that somehow, someway, he has found a way to circumvent the system.

He is OK with that.

"I'm always going to get questions asked of me,'' Byrd told USA TODAY Sports on Tuesday, "and I don't mind that. Really, I don't. I can't. I hear the questions:

"What is he doing?

"Is he taking something?

"Is he cheating?''

Byrd says this all this without anger in his voice. There is no level of frustration. It will take time.

"I understand why people are skeptical,'' says Byrd, a popular player among his peers. "I just have to play hard and hopefully people will believe in me.''

Certainly, he knows why those in and around the game could find it incredulous that he's having this glorious season - a career-high 22 homers, 77 RBI, a trade from the languishing New York Mets to the contending Pittsburgh Pirates - without the benefit of performance-enhancing drugs.

Yes, he received a 50-game suspension in June 2012 for taking performance-enhancing drugs, and never returned to the big leagues.

Yes, he is close friends with Victor Conte, the founder of BALCO, and has taken Conte's legal supplements since 2008.

Yes, his agents are Sam and Seth Levinson of ACES, who are under investigation by Major League Baseball after a former employee, Juan Nunez, was directly involved with more than 10 players who were linked to the Biogenesis scandal.

Oh, and he's having the greatest season of his 12-year career, a year that likely will culminate with his first playoff appearance.

And he's doing all this at of 36 - seven months after playing in Mexico.

"You put all those factors in,'' Byrd says, "It's like, 'OK, how is he doing it? You're not supposed to be getting better with age?'"

He welcomes all inquiries.

The National League's overwhelming favorite for Comeback Player of the Year already has been subjected to four drug tests this year, and now that the Pirates are closing in on their first postseason berth in 21 years, there will be more coming.

The scrutiny was actually worse back in 2009, when Byrd played for the Texas Rangers. He revealed that he was a regular customer of Conte's taking supplements from his SNAC company in Burlingame, Calif.

The next thing Byrd knew, he was taking 11 drug tests that season alone.

"That goes with the territory,'' Conte told USA TODAY Sports on Tuesday. "If you're clean, you don't care how often they come. There's no ducking anything with Marlon.

"If you have something to hide, you're certainly not going to let it be publicly known that you are associating with me, because you put a target on your back.''

Says Byrd: "The easiest thing for me to have done is cut ties with Victor. To cut ties with Sam and Seth. But you only do that when you're guilty of something. You don't get rid of family. We all stuck together.''

Byrd insists that he has never taken steroids, human growth hormone or testosterone.

He did use Tamoxifen, most commonly used to treat breast cancer, and tested positive last year, ending his season. For athletes, the drug counteracts the side effect of enlarged breasts often caused by using steroids, but Byrd said then he took it for a condition called gynecomastia, which was caused when he lost 35 pounds during the winter of 2011.

"I have a condition, and I was taking that,'' Byrd says, "It was just me not doing my due diligence. It was me being stupid.''

He was released by the Red Sox two weeks before his positive test; though he was eligible forreinstatement Aug. 21, no one was interested.

He went home to Calabasas, Calif. and told his agents to find a team in Mexico. He left Sept. 26 for spring training in Tijuana, and spent four months playing for Culiacan .

He changed his hitting mechanics, even his grip to create extension. He began driving the ball to all fields.

And still, no calls.

"It was like, 'Oh, he must be done. He's finished,' '' Byrd says. "I refused to believe it. I knew I could still play.''

Finally, in early February, the Mets invited Byrd to their spring-training camp. They would pay him $700,000 - $200,000 more than the minimum - and only if he made the opening-day roster. Byrd accepted, knowing it likely would be his final shot.

"You only need one team to believe in you,'' Byrd said, "and the Mets were that team. I'll be grateful to them for the rest of my career.''

And now, he has found redemption, perhaps providing a path for the 14 players suspended for using performance-enhancing drugs in the Biogenesis investigation.

It won't be easy, Byrd knows. Brewers outfielder Ryan Braun, in particular, is going to be a target. He's got a huge contract. He's a former MVP. And he let down those, particularly his peers, who believed in him.

"He'll hear the boos," says Byrd. "The steroid chants. Maybe even out at dinner, on the road, people saying stuff. That's where it will be difficult.

"It will take a year, maybe two or three years, it will be gone. He's already done his apology. How much more can you punch a guy?''

Byrd's proof that even after absorbing a body blow, it's still possible to stand tall.